Navigating the transition in municipal solid waste management systems

Abstract

Similar to other sustainability transitions, the shift from landfilling to more sustainable waste treatment methods in municipal solid waste management (MSWM) is a complex process. In an interconnected and rapidly developing world with evolving conditions within and outside MSWM, along with increasing uncertainties, landfill diversion requires robust solutions and a broad systemic perspective. This dissertation addresses these challenges while exploring landfilling alternatives that support climate change mitigation and resource efficiency as sustainability goals. The work examined several aspects of the transition, namely, economic, environmental, transition speed, behavioural and governance, using a combination of methods. In particular, life cycle assessment and life cycle costing were used to evaluate the environmental and economic performance of MSWM transition pathways and the speed of greenhouse gas (GHG) emission reduction. Sensitivity and uncertainty analyses, including uncertainty decomposition, were applied to assess the robustness of different landfilling alternatives under variable conditions. A system-wide view of the transition is supported by applying the multi-level perspective— a framework commonly used to study sustainability transitions—while examining the factors influencing the MSWM transition. This dissertation also investigated the determinants of waste source-separation behaviours. The findings of the research conducted within this dissertation underscore the need for robust solutions in MSWM transitions, as the best-performing alternatives vary under changing conditions and associated uncertainties. Advanced sensitivity and uncertainty analyses, complemented by uncertainty decomposition, show potential for identifying robust solutions, as demonstrated by their application to the analysis of uncertainties in GHG emission reduction costs. Furthermore, the speed of GHG emission reduction for landfill alternatives is shown to be overridden by the state and uncertainty of other parameters within and beyond the MSWM system. Finally, the analysis of factors influencing the MSWM transition reveals that many barriers lie outside the control of MSWM itself and may require the alignment of agendas with other systems, thus emphasising the importance of considering a broader systemic perspective in navigating current MSWM transitions.